Aggression is the most common and least transitory of childhood dysfunctions. Whereas traditional treatments have had little success, recently developed approaches involving training the aggressive child's parents in social learning theory-derived strategies and techniques of child management have shown considerable promise. Clinical studies including ones by the Oregon Social Learning Center (OSCL) have demonstrated that such interventions do cause significant and durable changes in the aggressive child. One project at OSLC has been implementing and evaluating this treatment in real-world settings. One such effort in Helena, Montana, successfully replicated previous research while displaying cost efficiency. Other recent field tests, however, indicate that deficiencies in training and posttraining supervision can undermine the program such that it is not significantly superior to nonsocial learning intervention. The proposed work, seeks to address weaknesses in the current implementation procedures and then evaluate apprenticeship versus intensive workshop training and the use of an agency person trained in the program and acting as supervisor of the line-level trainees on the implementation of the model in eight mental health settings. Therapists will be evaluated with criterion referenced measures of clinical performance. Child and family behavior will be assessed using a series of previously developed and validated outcome measures. Trainee performance and client outcomes will be compared with previous successful and unsuccessful tests. This project should pave the way for wider, more effective dissemination.